1997 F150 transmission issue

[Peacock]

Very well could.

The VSS input is used for a multitude of transmission controls. From EPC solenoid duty cycle to TCC valve duty cycle to shift solenoid managing.

 

[deerefan]

Very well could.

The VSS input is used for a multitude of transmission controls. From EPC solenoid duty cycle to TCC valve duty cycle to shift solenoid managing.

The erratic shifting started when light started blinking, so hopefully this is it. Thanks for all the help!

 

[deerefan]

Well darn. The needle still twitchy, shifting weird and the o/d light is blinking still. Is there a speed sensor on the trans tail shaft?

 

[sld]

If no code is showing, or if it was and you read it, disconnect both battery terminals and give them a good cleaning.

It's a good thing to do and it will reset your system. If the issue still persists, it has to be storing a code.

The VSS's do go bad so it was a good thing to replace anyway. Reset your system and see what happens next.

 

[Soundguy]

does that model have a GEM module?

the gem in my 99350 got wet from a leaky canopy lamp base.. and gave me a twitchy rpm needle and blinking od lamp

 

[allen6634]

the frist thing i would check is the speed-o sensor, i would think the tranny is comp. controlled, if it is't getting the right info about the truck speed, then it will go nuts

 

[94BULLITT]

Take it to a repeatable shop and have them scan it. Those clowns at the parts stores don't know what they are doing.

 

[geblackwell]

Had a 1997 f150 that did the same thing after it had 100,000 miles on it. At that time the shop that worked on mine said this was common. Their solution was change the fluid and put in some type of additive. This worked for several thousand miles, but was starting to return when I traded it.

 

[Soundguy]

that sounded like a slip.. and they put in a friction modified fluid.

not sure this si the same issue with a blinking OD lamp...

 

[rsallen]

Speedo/instrument cluster?
Possible ECM.

Be sure to check all the others, wiring, sensors etc.